Key to species of Chaetogammarus

1. Antenna 1 accessory flagellum bi-articulated ... C. warpachowskyi

- Antenna 1 accessory flagellum at least three articles ... 2

2. Pleosome covered with small spines ....... C. hyrcanus

- Pleosome bare ............................................................ 3

3. Eyes very elongated and constricted in the middle ... C. placidus

- Eyes regular (reniform) .............................................. 4

4. Antenna 1 and 2 set with dense setae longer than the underlying segment ............................................ C. ischnus

- Antenna 1 and 2 set with sparse setae shorter/equal with the underlying segment ................................... C. pauxillus